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Kem WR, Soti F, Rocca JR, Johnson JV. New Pyridyl and Dihydroisoquinoline Alkaloids Isolated from the Chevron Nemertean Amphiporus angulatus. Mar Drugs 2024; 22:141. [PMID: 38667758 PMCID: PMC11050936 DOI: 10.3390/md22040141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/18/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024] Open
Abstract
Nemertean worms contain toxins that are used to paralyze their prey and to deter potential predators. Hoplonemerteans often contain pyridyl alkaloids like anabaseine that act through nicotinic acetylcholine receptors and crustacean chemoreceptors. The chemical reactivity of anabaseine, the first nemertean alkaloid to be identified, has been exploited to make drug candidates selective for alpha7 subtype nAChRs. GTS-21, a drug candidate based on the anabaseine scaffold, has pro-cognitive and anti-inflammatory actions in animal models. The circumpolar chevron hoplonemertean Amphiporus angulatus contains a multitude of pyridyl compounds with neurotoxic, anti-feeding, and anti-fouling activities. Here, we report the isolation and structural identification of five new compounds, doubling the number of pyridyl alkaloids known to occur in this species. One compound is an isomer of the tobacco alkaloid anatabine, another is a unique dihydroisoquinoline, and three are analogs of the tetrapyridyl nemertelline. The structural characteristics of these ten compounds suggest several possible pathways for their biosynthesis.
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Affiliation(s)
- William R. Kem
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - Ferenc Soti
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - James R. Rocca
- Advanced Magnetic Resonance Imaging and Spectroscopy Facility, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA;
| | - Jodie V. Johnson
- Mass Spectrometry Research and Education Center, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA;
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Kem WR, Rocca JR, Johnson JV, Junoy J. Discovery of the Nicotinic Receptor Toxin Anabaseine in a Polystiliferan Nemertean. Toxins (Basel) 2023; 15:46. [PMID: 36668866 PMCID: PMC9867080 DOI: 10.3390/toxins15010046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/25/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
Nemerteans (also called Nemertines) are a phylum of predominantly marine worms that use toxins to capture prey and to defend themselves against predators. Hoplonemerteans have a proboscis armed with one or more stylets used in prey capture and are taxonomically divided into Order Monostilifera, whose members possess a single large proboscis stylet, and Order Polystilifera, whose members have multiple small stylets. Many monostiliferans contain alkaloidal toxins, including anabaseine, that stimulate and then desensitize nicotinic acetylcholine receptors that are present in all animals. These compounds also interact with pyridyl chemoreceptors in crustaceans, reducing predation and larval settlement. Anabaseine has been a lead compound in the design of alpha7 nicotinic acetylcholine receptor agonists like GTS-21 (also called DMXBA) to treat disorders of cognition such as Alzheimer's disease and schizophrenia. These drug candidates also display anti-inflammatory activities of potential medical importance. Most polystiliferans live deep in open oceans and are relatively inaccessible. We fortunately obtained two live specimens of a large benthic polystiliferan, Paradrepanophorus crassus (Pc), from the coast of Spain. MS and NMR analyses of the Ehrlich's reagent derivative allowed identification of anabaseine. A spectrophotometric assay for anabaseine, also based on its reaction with Ehrlich's reagent, revealed high concentrations of anabaseine in the body and proboscis. Apparently, the biosynthetic mechanism for producing anabaseine was acquired early in the evolution of the Hoplonemertea, before the monostiliferan-polystiliferan divergence.
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Affiliation(s)
- William R. Kem
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - James R. Rocca
- AMRIS, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Jodie V. Johnson
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Juan Junoy
- Departamento de Ciencias de la Vida, Universidad de Alcalá, 28805 Alcalá de Henares, Spain
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Turner AD, Fenwick D, Powell A, Dhanji-Rapkova M, Ford C, Hatfield RG, Santos A, Martinez-Urtaza J, Bean TP, Baker-Austin C, Stebbing P. New Invasive Nemertean Species ( Cephalothrix Simula) in England with High Levels of Tetrodotoxin and a Microbiome Linked to Toxin Metabolism. Mar Drugs 2018; 16:E452. [PMID: 30453540 PMCID: PMC6266807 DOI: 10.3390/md16110452] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 12/21/2022] Open
Abstract
The marine nemertean Cephalothrix simula originates from the Pacific Ocean but in recent years has been discovered in northern Europe. The species has been associated with high levels of the marine neurotoxin Tetrodotoxin, traditionally associated with Pufferfish Poisoning. This study reports the first discovery of two organisms of C. simula in the UK, showing the geographical extent of this species is wider than originally described. Species identification was initially conducted morphologically, with confirmation by Cox 1 DNA sequencing. 16S gene sequencing enabled the taxonomic assignment of the microbiome, showing the prevalence of a large number of bacterial genera previously associated with TTX production including Alteromonas, Vibrio and Pseudomonas. LC-MS/MS analysis of the nemertean tissue revealed the presence of multiple analogues of TTX, dominated by the parent TTX, with a total toxin concentration quantified at 54 µg TTX per g of tissue. Pseudomonas luteola isolated from C. simula, together with Vibrio alginolyticus from the native nemertean Tubulanus annulatus, were cultured at low temperature and both found to contain TTX. Overall, this paper confirms the high toxicity of a newly discovered invasive nemertean species with links to toxin-producing marine bacteria and the potential risk to human safety. Further work is required to assess the geographical extent and toxicity range of C. simula along the UK coast in order to properly gauge the potential impacts on the environment and human safety.
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Affiliation(s)
- Andrew D Turner
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | | | - Andy Powell
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Monika Dhanji-Rapkova
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Charlotte Ford
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Robert G Hatfield
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Andres Santos
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
- Laboratory of Applied and Molecular Biology, Avenida Alemania 0458, 4810296 Temuco, Chile.
- Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Avenida Francisco Salazar 01145, 4811230 Temuco, Chile.
| | - Jaime Martinez-Urtaza
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Tim P Bean
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Craig Baker-Austin
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
| | - Paul Stebbing
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, Weymouth, Dorset DT4 8UB, UK.
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Stricker SA, Ravichandran N. The potential roles of c-Jun N-terminal kinase (JNK) during the maturation and aging of oocytes produced by a marine protostome worm. ZYGOTE 2017; 25:686-96. [PMID: 29032774 DOI: 10.1017/S0967199417000533] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Previous investigations have indicated that c-Jun N-terminal kinase (JNK) regulates the maturation and aging of oocytes produced by deuterostome animals. In order to assess the roles of this kinase in a protostome, oocytes of the marine nemertean worm Cerebratulus were stimulated to mature and subsequently aged before being probed with phospho-specific antibodies against active forms of JNK and maturation-promoting factor (MPF). Based on blots of maturing oocytes, a 40-kD putative JNK is normally activated during germinal vesicle breakdown (GVBD), which begins at 30 min post-stimulation with seawater, whereas treating immature oocytes with JNK inhibitors downregulates both the 40-kD JNK signal and GVBD, collectively suggesting a 40-kD JNK may facilitate oocyte maturation. Along with this JNK activity, mature oocytes also exhibit high levels of MPF at 2 h post-stimulation. However, by ~6-8 h post-GVBD, mature oocytes lose the 40-kD JNK signal, and at ~20-30 h of aging, an ~48-kD phospho-JNK band arises as oocytes deactivate MPF and begin to lyse during a necroptotic-like mode of death. Accordingly, JNK inhibitors reduce the aging-related 48-kD JNK phosphorylation while maintaining MPF activity and retarding oocyte degradation. Such findings suggest that a 48-kD JNK may help deactivate MPF and trigger death. Possible mechanisms by which JNK activation either together with, or independently of, protein neosynthesis might stimulate oocyte degradation are discussed.
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Strand M, Hedström M, Seth H, McEvoy EG, Jacobsson E, Göransson U, Andersson HS, Sundberg P. The Bacterial (Vibrio alginolyticus) Production of Tetrodotoxin in the Ribbon Worm Lineus longissimus-Just a False Positive? Mar Drugs 2016; 14:md14040063. [PMID: 27023570 PMCID: PMC4849067 DOI: 10.3390/md14040063] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 12/19/2022] Open
Abstract
We test previous claims that the bacteria Vibrio alginolyticus produces tetrodotoxin (TTX) when living in symbiosis with the nemertean Lineus longissimus by a setup with bacteria cultivation for TTX production. Toxicity experiments on the shore crab, Carcinus maenas, demonstrated the presence of a paralytic toxin, but evidence from LC-MS and electrophysiological measurements of voltage-gated sodium channel-dependent nerve conductance in male Wistar rat tissue showed conclusively that this effect did not originate from TTX. However, a compound of similar molecular weight was found, albeit apparently non-toxic, and with different LC retention time and MS/MS fragmentation pattern than those of TTX. We conclude that C. maenas paralysis and death likely emanate from a compound <5 kDa, and via a different mechanism of action than that of TTX. The similarity in mass between TTX and the Vibrio-produced low-molecular-weight, non-toxic compound invokes that thorough analysis is required when assessing TTX production. Based on our findings, we suggest that re-examination of some published claims of TTX production may be warranted.
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Affiliation(s)
- Malin Strand
- Swedish Species Information Centre, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden.
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, 75237 Uppsala, Sweden.
| | - Martin Hedström
- Division of Biotechnology, Lund University, 22100 Lund, Sweden.
| | - Henrik Seth
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530 Gothenburg, Sweden.
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530 Gothenburg, Sweden.
| | - Eric G McEvoy
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L32AJ, UK.
| | - Erik Jacobsson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, 75237 Uppsala, Sweden.
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, 75237 Uppsala, Sweden.
| | - Håkan S Andersson
- Linnaeus University Centre for Biomaterials Chemistry, Department of Chemistry and Biomedical Sciences, Linnaeus University, 39234 Kalmar, Sweden.
| | - Per Sundberg
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530 Gothenburg, Sweden.
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Stricker SA, Beckstrom B, Mendoza C, Stanislawski E, Wodajo T. Oocyte aging in a marine protostome worm: The roles of maturation-promoting factor and extracellular signal regulated kinase form of mitogen-activated protein kinase. Dev Growth Differ 2016; 58:250-9. [PMID: 26918273 DOI: 10.1111/dgd.12269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 12/29/2015] [Accepted: 01/10/2016] [Indexed: 12/15/2022]
Abstract
The roles of maturation-promoting factor (MPF) and an extracellular signal regulated kinase form of mitogen-activated protein kinase (ERK MAPK) are analyzed during oocyte aging in the marine protostome worm Cerebratulus. About a day after removal from the ovary, unfertilized metaphase-I-arrested oocytes of Cerebratulus begin to flatten and swell before eventually lysing, thereby exhibiting characteristics of a necroptotic mode of regulated cell death. Based on immunoblots probed with phospho-specific antibodies, MPF and ERK are initially active in freshly mature specimens. However, as oocytes age, both kinase activities decline, with ERK deactivation occurring well before MPF downregulation. Experiments using pharmacological modulators indicate that oocyte degradation is promoted by the maturation-initiated activation of ERK as well as by the deactivation of MPF that occurs in extensively aged specimens. The potential significance of these findings is discussed relative to previously published results for apoptotic eggs and oocytes of echinoderm and vertebrate deuterostomes.
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Affiliation(s)
- Stephen A Stricker
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131, USA
| | - Bradley Beckstrom
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131, USA
| | - Cristina Mendoza
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131, USA
| | - Emma Stanislawski
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131, USA
| | - Tewodros Wodajo
- Department of Biology, MSC03 2020, 1 University of New Mexico, Albuquerque, NM, 87131, USA
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Chung BM, Stevens RC, Thomas CL, Palmere LN, Okazaki RK. Preliminary Report of a Neurokinin-Like Receptor Gene Sequence for the Nemertean Paranemertes sp. Zoolog Sci 2015; 32:567-70. [PMID: 26654039 DOI: 10.2108/zs150081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tachykinins (TKs) are a family of neurotransmitters that function as signaling molecules for such processes as maintaining homeostasis, regulating stress response, and modulating pain. TKs require the expression of at least one of three receptor subtypes: Neurokinin Receptor-1 (NKR-1), Neurokinin Receptor-2 (NKR-2), or Neurokinin Receptor-3 (NKR-3). We have isolated and cloned a portion of a gene coding for a tachykinin-like receptor from the nemertean Paranemertes sp. This 488-bp portion contains a short 101-bp segment that shares 85% similarity to the mouse substance-K receptor in Mus musculus and 83% similarity to the moth neuropeptide receptor A24 in Bombyx mori. Translated homology analysis aligning the coding sequence with the initial cytoplasmic carboxyl terminus of numerous G-protein coupled neuropeptide receptors also revealed 73% similarity to B. mori neuropeptide receptor A24. Our finding is the first report of a sequence amplified from Paranemertes sp. that may code for a small portion of a G-protein-coupled neuropeptide receptor with significant similarity to the TKR family, particularly the NKR-3 receptor isoform. This novel finding may open new avenues into exploring the role of tachykinin and its receptor in nemertean neurophysiology.
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Affiliation(s)
- Brian M Chung
- Department of Zoology, Weber State University, 1415 Edvalson Street; Department 2505, Ogden, UT 84408-2505, USA
| | - Rainee C Stevens
- Department of Zoology, Weber State University, 1415 Edvalson Street; Department 2505, Ogden, UT 84408-2505, USA
| | - Chelsie L Thomas
- Department of Zoology, Weber State University, 1415 Edvalson Street; Department 2505, Ogden, UT 84408-2505, USA
| | - Laura N Palmere
- Department of Zoology, Weber State University, 1415 Edvalson Street; Department 2505, Ogden, UT 84408-2505, USA
| | - Robert K Okazaki
- Department of Zoology, Weber State University, 1415 Edvalson Street; Department 2505, Ogden, UT 84408-2505, USA
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